Method and apparatus for screening wet material



May 15, 1928. 1,669,973

I J. CREDO METHOD AND APPARATUS FOR, SCREENING WET MATERIAL Filed Dec.4, 1926 J J T 12 1 II J r i i/ 10 ga vanic; 7 J M.

JULIUS canno, or noursvnmn, xnnrucxy,

cnmnmr co. me,- or LQUISVILLE, marten,

J Application filed December a method for My invention relates to ch asdistillery screening wet materials su slop, paper pulp, cotton hnters,rubber, etc., and the object thereof is to I) provide a more economicaland efiicient method of reclamation, which method is particularlycharacterized by the prevention of formation of channels in the layer.

Another object of the invention is to proln vide an apparatus in whichthe. la er on the screen is maintained substantial y uni form inthickness while the wet material progresses over the screen.

In the usual type of screen box thev material slides down the perforatedmetal which. forms the screen, very slowly, and the watery materialusually channels through the layer of filtered substance therebyreducing'the filtering effect and creating not I only a loss offine-material but also reducing the capacity of the screen. To avoidthis, I provide a spreader over the screen which prevents the formation0 channels and furthermore maintains the layer on thescreensubstantially uniform in thickness throughout;

In the appended drawing forming part of this application, Figure 1 is avertical sec tion on line 1-1 of Figure 2 of a screening apparatusembodying my invention, and

Figure 2 is a plan View of the apparatus. Re erring to the drawing 5- isa box which is divided transversely by a. partition 8 into an uppersection 6 and a lower section 7 both sections of the box being coveredby a a screen 9. The box is supported at an angle 1 such that materlal,fed on to the screen will screen, WhlCh consists- 1n eedmg wetmaprogress ravitationally. v A- fee g trough 10 is provided at theupperpart ofthe section 6 of the box.5.. Said section 6 has an outlet 11at its lower end, which leads to a trough 12, disposed to discharge onthe screen 9 in proximity of the partitionj8, over the section 7 of the.-box. The section 7 o'fthebox-has also an outlet I 13, to carry off"the material thatv terialgravitationally on the screen, spreadpassesthrough the screen; g

To prevent formation of,= channels in.the. layer of materialtravelingy'gravitationally on the screen 9, I. provide a spreader in theform of paddles 14"which travel over the screen 9. The'padd-les arecarried by chains 15, engaged by. suitable sprockets 16 to which motionis im arted from a. drive s rocket 17.

The pad es 14are .maintaine in their reclaimed a conronarroiw orKENTUCKY.

im'rnon m arrm'rus roa scnnnmnc wE'r MATERIAL.

4, 1926. Serial no. 152,561.

movement over the screen 1n a plane arallel thereto by supporting therow of pa dles at the screen on a suitable ledge 18, provided nssrcnoa"r0 LOUISVILLE mime MA- 1.6 1 Tas PATENT OFFICE.

on the side of the structure which carries the spreader mechanism.

The paddles of the spreader progress in the same direction asthematerial as I have 'foundthat the angle of repose of the partlydriedsubstance is usually steeper than can be obtained in any practicalapparatus.

By dividing the box 5 into two sections so that the upper section feedsover to the lower section, I get the effect of a double filtration ofthe material fed on to the screen. This double filtration removes to aeat extent, thefine material which is carried out with the filtrate inthe first screenin and therefore, increases the efliciency. a matter offact the filtering is not done by the perforated screen except I by theupper part of the screen but is actually done by the layer of solids onthe screen. It is, for this uniform and therefore, its efliciency 'over'the screen is substantially the same, andby the use; of the spreadersuch a screen is rendered so eflicient that secondary press ing, whichis done on a roller press is obviated. Further it usually increases thecapacity of a plant because of the almost perfect recovery of theextremely fine substances. y

I claim: p

1. A method for filterin material on a terial gravitationally over ascreen, maintaining the material in a substantially uniform layer whilemoving on the screen 001- ortion lecting material assed throu h a of thescreen an returning it to t e, material on the remaining portion of thescreen.

2. A method for filtering wet material on a screen which consistsinfeeding the maing the material on the screen in the,direction of itsmotion to prevent channelling f reason that the double filtration isresortterial on the remaining portion of the screen. k

3. An apparatus for filtering wet material comprising a-screen on whichthe ma- 2 neeepvs terial 'moves gravitationally, a' main terial movesgravitationally, a main fee&

for wet material to 'the screen nearest the for wet material to thescreen nearest the highest point of the screen, a boxfor 001- high pointof the screen, a box for collect lecting material that passes throu h aporlngmaterial that passes'through a, higher 15 I 'tion of the screen, asecondary eed from portion of-the screen, a secondary grit/vita the boxto the screen toI-deliven material for tionalfeed from the box tothevlower rethe remaining portion ofthe screen, in ad-' maining portionof the screen, and means 'dition to the ma erial delivered from thetravelling over the entire screen for mainmain feed. I staining auniform layer of material thereon, 4.-An apparatus'for filtering'wetmatei rial comprising a screen on which the ma-' I JULIUS CREDO,

